


Work It Harder, Make It Better

by IdleSin (inkstainedwretch)



Series: Metal and Magic [5]
Category: Undertale (Video Game)
Genre: Begging, D/s elements, Ghost Smooching, Hair Pulling, Interchangeable Robot Genitalia, Other, Reader has a vulva, Strap-Ons, Vaginal Fingering, Voice Glitches, ghost family is the best family, heart goo, ridiculous fluff, we all just want to hug blooky
Language: English
Status: Completed
Published: 2016-01-13
Updated: 2016-01-13
Packaged: 2018-05-13 17:30:23
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,047
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5710984
Author URL: https://archiveofourown.org/users/inkstainedwretch/pseuds/IdleSin
Summary: <blockquote class="userstuff">
              <p>You have a new piece of hardware you'd like Mettaton's input on. As it happens, so does he.</p>
<p>[Reader has a vulva, but no gendered pronouns are used. There's also no specific chest stuff (mentions of bras, etc.), in case that's a concern of yours.]</p>
            </blockquote>





	Work It Harder, Make It Better

The bands are surprisingly comfortable on your wrist, and they flex easily when you bend them. The readings on your monitor are consistent, so the signal should be transferring without gaps. Perfect. Now all you need to do is wait for your test subject to arrive.

You poke your head around the corner to make sure Mettaton can't see you. He's been chatting with Alphys at her work table for the past half hour or so, talking an awful lot about power efficiency and how to make something more sturdy (you're not sure what). It's been a serious pain trying to keep this from him, but you wanted this to be a surprise.

"It doesn't have to actually _fire_ ," Mettaton sighs behind you. "We're only ever going to use it on stage."

"Well," you hear the sound of Alphys's claws tapping against the table. "In that c-case, maybe we can just put some kind of laser lights there so it _looks_ like it's doing something?"

The door to the lab opens behind you, and your new lab assistant greets whoever just arrived.

"hOI!" she calls out happily. "welcom 2...DA LAB!!!"

"H-hey... I didn't know you worked here..."

"Napstablook!" You turn around and wave them over. "Just who I wanted to see."

"I got your text..." they hover over to you, looking a little nervous. "I didn't know if you wanted me to bring anything. I'm sorry if I forgot something..."

"I didn't need you to bring anything but yourself," you reassure them.

"Blooky...?" Mettaton leans back a little so he can see you both. "What are you doing all the way out here?"

"I invited them," you explain, adjusting the bands on your wrists to make sure they aren't moving. "Thanks for agreeing to help me test this out, Blook."

"Sure thing..." Napstablook looks at the screen on your table, where the readings are still strong. "This isn't...gonna hurt, is it?"

"It shouldn't," you frown, turning the dial down on the generator just in case. "Okay. Now all you need to do is hold still. I'm going to touch your head."

"What?" they look confused. "You're just gonna phase right through me, aren't you?"

"Maybe," you concede. "Hopefully not. Tell me if it hurts, okay?"

They nod, and slowly you reach a hand out and hover it gently over their head. You take a deep breath, check to make sure the energy reading is still constant, and bring your hand down. You take care to avoid their face, and the palm of your hand begins to feel cold...and then it stays. It's like touching a cloud, impossibly light, but solid.

"Okay," you take a deep breath, suddenly incredibly nervous. "How does that feel?"

Napstablook doesn't answer for a long moment, and you begin to panic, thinking you've hurt them somehow. You begin to withdraw your hand, and they jump.

"No!" They rush forward, then stop quickly. "I-I mean...sorry. I should have said something."

"Are you okay?" you ask, and in the corner of your eye you can see Mettaton bounding towards you.

"Yeah," they nod. "I'm okay... I just didn't expect that to feel..."

"Blooky," Mettaton skids a little on the tile as he comes to a stop beside you. "Are you alright? Are you hurt?"

"No!" They shake their head. "It was just...so warm. Can...can you maybe do that again?"

You nod, holding your hand out again, and this time they move toward you. They nuzzle into your hand, and you see tears begin to form at the corners of their eyes, but they're smiling.

"This is nice," they lean forward so their body touches more of your arm.

"Good," you smile broadly, feeling happiness well up in your chest. "Can we maybe try more?"

"Like what?"

Napstablook and Mettaton speak at the same time, one curious and the other concerned. You look at Mettaton with what you hope is a reassuring smile.

"Could I hug you?" you ask, and Napstablook's eyes go wide.

"I-I mean...do you think that would work?"

"Maybe," you shrug. "It's worked so far."

"Okay," they nod, their smile faltering.

You check both your monitor and Mettaton's expression before proceeding. The monitor looks fine; Mettaton looks gobsmacked. Nevertheless, you take a step forward and slowly wrap your arms as far around Napstablook as you can reach. When you begin to close them, the soft chill presses gently against your arms, but they stay put. Your eyes go wide. You honestly didn't think it would work on the first try.

"Oh my gosh," Napstablook whispers. " _Oh my gosh_."

"How do you feel?" you ask, hoping this isn't too much for them.

"This is so great," their voice is a breathless squeak, and your shoulder starts to feel wet.

You worry for a second about ghost tears being harmful, but if you remember right they only hurt if they touch your soul. You decide to test one more thing, and gently you lean your head down until it rests on top of theirs. They press a little closer into you, and you can't help but smile. After a moment, you withdraw, and Napstablook has never looked so bright.

"Could that work with...someone else?" They ask, and you nod.

"I actually designed them for Mettaton."

Mettaton looks taken aback, but when you remove the bands from your wrists and hand them to him, he slides them on with little trouble. The screen flickers for a moment as the energy readjusts to its new wearer, but then it settles again. You feel no small amount of pride; the hardest part of this had been figuring out how it would react to a robot wearer instead of a human.

"So," he begins, sounding unusually hesitant, "should I just...?"

He looks at his hands as if unsure what to do with them, and Napstablook doesn't even wait for you to answer before flying straight into his arms. The force of it actually pushes Mettaton back an inch or so, and while it's not your preferred method of testing it out, it works. Mettaton's eyes begin to flicker as he wraps his arms around them, but when he gives them a gentle squeeze and doesn't even start to phase through, his heart begins to glow.

"Blooky, don't cry," Mettaton whispers. "It's alright. I'm here."

"I'm s-sorry," they don't seem to be able to take Mettaton's advice. "I j-just can't...b-b-believe it. It's been s-so long since I could hug you..."

"It has," his hand begins to rub soothing circles into their back. "I've missed it."

You feel a hand on your back, and you turn to see Alphys standing next to you, her eyes brimming with tears. You pat her gently on the shoulder and yeah, maybe you sniff a little. At this point, who can blame you?

You and Mettaton end up taking Napstablook back to their house, much later after you've tried to make at least some science out of the afternoon. You may have to end up admitting in your report that this was mostly a personal interest, but you're not too upset about that. When you finally leave so Blooky can get some rest, Mettaton waits until you're far enough away that they won't hear you before speaking.

"When you said you designed them for me..." he begins, but he doesn't seem inclined to finish the sentence.

"I just kept thinking about Napstablook's wish from the festival," you say, hoping that's what he's asking. "They missed being able to touch you."

"I see," he nods slowly. "For a moment I thought perhaps you made them so you could touch _me_."

You furrow your brows and blink a few times, trying to figure out what the heck he means by that, but then you remember what he told you after the festival.

"Oh! No, that's not what I had in mind...I mean," you pause for a moment, "I'd only try that if you wanted to."

He nods again, looking thoughtful, but he doesn't continue. You wonder what it would be like, if he could even leave his corporeal body in the first place. Given how frightened he was of telling you about his past self earlier, you decide not to press the issue. You made the wristbands to let him be close to his cousin again, and that's exactly what you accomplished.

Your eyebrows ping upwards, and you begin to giggle.

“What?” he looks sideways at you.

“I just realized,” you say, “I can probably try one of Napstablook’s sandwiches now.”

He laughs aloud, and if the sign on the wall doesn't make it clear that you've reached Hotland, the waves of heat that begin to wash over you certainly do.

“I’ll see you tomorrow, then?” you ask, heading toward the front door of the lab. “Or are you filming?”

"I should be back in the lab tomorrow," he takes your hand and kisses it lightly. "Although, if you're free for the rest of the evening, I'd love it if you'd come back to the resort with me."

There's a deliberate gleam in his eye, a small blinking of pixels near the corner of his pupil, and you know it means he has something in mind. Judging by the way he's smiling, it looks to be something he thinks you'll like.

"I'd love to," you reply, feeling your body begin to tingle with anticipation.

He doesn't say a word the whole way up to his suite, and when the door slides shut behind you, he brings you over to the sofa and has you sit down.

"Close your eyes, darling," he purrs. "I'll be right back."

You do so, and you can hear the click of his heels as he heads toward what sounds like the closet. You twist your fingers around each other, your knees beginning to bounce wondering what he has in mind. You hear his footsteps as he comes back, and then a rather heavy box is placed into your lap.

"I just got the demo models back from the manufacturer," he says excitedly, sitting down on the chaise next to you. "You can look now, sweetheart. I can't wait to see what you think of it~"

You open your eyes to see what looks like a plain black shoe box in your lap. You slide the top off, and inside sits perhaps the largest dildo you've ever seen. (To be fair, most of the ones you've seen in your life so far have been pretty average sized, but _still_.) It's long, thick but tapered slightly, and when you pick it up it has considerable weight to it. It feels like the same silicone he's made all his other toys out of, somewhat soft on the outside but with a firm center. The base is curved, with a small bulb extending upward at an angle, likely meant to be inserted by the wearer but not near big enough to support it without a harness. Sure enough you can see a harness resting underneath, gleaming black with thick, sturdy straps. It probably had to be specially designed to support the weight of the toy.

"Holy shit," you whisper.

"Do you like it~?" he leans forward a little.

"Yeah," you nod, your mind already coming up with a hundred delicious ideas. "Yeah, I really do." 

"Marvelous," he gives your hand a tug, drawing you over to his bed.

He undresses you lovingly, pressing worshipful kisses to the new areas of skin he uncovers. The harness is snug against your body, but the material it's made of is soft enough not to dig into your skin. There's a soft click as his heart container opens, and he coats his fingers in the liquid already dripping from it to make it easier to slip the bulb inside you. Once the toy rests securely in its place, you can feel the base of it conform to your body, the soft material pressing up against your clit.

"God damn," you laugh softly. "You thought of everything."

"I'm glad you like how it fits," he trails his fingertips up the underside of the shaft, leaving trails of bright pink behind. "Now, come here."

He pulls you down on top of him, clicking open the plates between his legs, and now that you get a good look at how the toy looks next to his body, you realize just how big it actually is.

"...are you sure?" you ask, looking back and forth between the toy and him. "It's kind of huge."

"That would be the point, darling." He draws you down for a kiss, whispering the words against your lips. "I want you to _wreck me_."

His words light a fire in you, and you get a grip on his shoulders and pin him to the bed, kissing him roughly. You feel one of his legs start to wrap around you, and it's clear that he really wants this. You almost give it to him...but if he wants you to really wreck him, it's going to take a little more than that. You feel unusually powerful, and it might go to your head just a little, but suddenly there's nothing you want more than to see how far you can push him.

His heart container is still open, and you move one hand down to drag over the surface of his soul. He shivers and gasps, but when your hand keeps moving he looks down at you with some confusion. You just smile in response, moving down and slipping your fingers inside him while your tongue attends to his heart. It's warm and sweet and in serious danger of flooding its container, and when you curl your fingers upward a surge of fluid hits your tongue.

"D-darling, what..." Mettaton tries to sit up a little, looking down at you with some confusion.

"Stay down." Your voice sounds low and firm, not something you're really used to, but you like it.

He looks surprised, but he does as he's told, leaning back against the pillows. You take the tip of his heart into your mouth and suck lightly, moving your fingers a little faster. His head falls to one side and he moans loudly, his hands grasping at the sheets. He looks down at you again, and his eyes are beginning to flicker.

"Are you...are y-you not going to..." he gasps.

"Hmm?" you hum softly, your mouth still on his heart, and he moans again.

"A--- _ah!_ That isn't-tttt fair!" You feel him clench once around your fingers. "You're going to - darling, if you keep d-d-doing that..."

The way his voice is already starting to skip and stutter has you furiously turned on, and your body feels like now would be a fine time to remove your hand and fuck him into the mattress. Your brain has other ideas, however, and so you lift your mouth away for a moment.

"What?" You curl your fingers again, twisting your hand a little so your thumb brushes his clit. "Am I gonna make you come? Isn't that what you want?"

"Nnnnngh-" his head snaps back, his voice turning into an incoherent buzz for a moment. "I thought y-y--ou - I www-want you to - darling, _please_..."

"Please what?"

You don't actually give him much chance to answer, taking hold of his heart with your other hand so you can bring it closer to your mouth. Your other hand begins to move faster, and you can feel warmth building up under your fingertips. You feel your tongue sink softly into his heart, and he screams, clenching rhythmically around your fingers as a warm gush of liquid covers your palm. His heart bursts with it, pulsing under your tongue, and you don't stop moving until he does. His hands unclench from the sheets and he looks up at you with pleading eyes, his heart container sliding shut.

"It's not enough," he whines, his face flushed with pink.

"It's not?" you ask teasingly, sliding back up so you can kiss him.

"I need more," he licks the fluid hungrily from your lips. "Please."

"Hmm," you shift your hips a little, sliding the tip of the toy against him. "You want this?"

" _Yesssss-s-s_ ," he groans. "I need it, darling, _please. Pleasepleaseplease-_ "

You run a hand through his hair and kiss him sweetly. "Since you asked so nicely..."

You roll your hips forward and slide into him, and he grabs at your shoulders with a broken shout. Every movement of your hips makes the toy rub against your clit, the bulb inside you pressing delightfully against your front walls, and when you glance down you can see that the shaft reaches all the way into his heart container, pushing up against his soul. Well, damn.

Mettaton pulls you closer, his legs bending and moving upward. The change in angle lets you go deeper, and he keens softly, burying his face in your neck.

"Fuck me," he hisses into your ear. " _Fuck me._ "

You pin him down by his shoulders again, using the leverage to hold him down as you drive into him harder. His head snaps to the side and he moans loudly, his voice skipping and getting stuck in repeat loops. The motion gives you an idea, and you get a hand into his hair and pull, using the other to hold onto his hip.

"Ohhh-h-h yessss," his eyes are half-shut and unfocused now. "Don't stop, don't stop, don't fffff- _fucking stop_..."

You couldn't if you tried, honestly. The sight of him like this, completely undone, clinging to you and moaning incoherently, is all the reason you need to keep going. There's so much liquid in his heart container that it's started to drip down his body in rivulets, meeting the liquid that flows out of him below, coating the surface of your shaft. He starts to gasp, his voice going higher and higher until it shorts out completely. A surge of fluid splashes against your hips, and when his voice comes back it clips and echoes over itself as he shakes hard underneath you. 

Your hips keep moving, every sound he makes fueling the fire inside your body. He's completely senseless, his fingers digging into your back as he writhes underneath you. His voice is broken into overstimulated static, and even though it's obvious his system can't handle it, he never lets go of you. Your teeth sink into the soft silicone of his neck and you come _hard_ , pushing into him hard enough to move you both a few inches up the bed. It takes a long, long while for the two of you to stop shaking, and even then you have to catch your breath before you slide out of him.

He doesn't say anything, doesn't even open his eyes, until his magic curls back into his heart in soft shimmering wisps. You brush one hand over his hair and kiss him tenderly, reaching down with the other to start sliding the harness off of your hips.

"I'd say that worked pretty nicely," your voice is a little hoarse, and it's not a surprise.

"Even better than I expected," he smiles lazily. "Far better than the trial runs."

"I'm flattered," you grunt a little as you remove the toy and set it aside. "Looks like both of our experiments were a success today."

"It does," he looks to one side, then back at you. "Speaking of which...now that I'm nice and relaxed, do you mind if we try something?"

"...sure," you roll onto your side so you're facing him, wondering what he has in mind.

"Here," he slides the bands off of his wrists and hands them to you, "and...please don't be alarmed."

His eyes slide shut, and you hear the fans inside his body begin to slow down. His heart dissolves in its container, which almost frightens you, but then a cloud of pink begins to take shape above him. In a few moments, you recognize the pink ghost from the photo in his old house. He's very cute, but he looks displeased.

"Are you alright?" you ask, sliding the wristbands on.

"I will be," he turns to face you. Without its computerized body, his voice echoes like his cousin's. "It's been a long time since I did this. I forgot what it feels like."

"Okay," you nod, making sure the bands fit despite knowing they're on correctly. You just want to be sure. "Just let me know what to do."

He nods, and his eyes close for a long moment. He hovers in place for a while, and if he had a body capable of it, he'd probably be taking very deep breaths. After a while, he opens his eyes.

"Alright," he says, sounding hesitant. "I didn't exactly think any further ahead than this. Just...repeat what you did with Blooky, perhaps?"

"Okay," you say again, and slowly reach a hand out. "Tell me if it doesn't feel right."

You lower your hand onto the side of his head, and once again it makes contact. He feels cold and light, just like Napstablook did, but it's a brighter kind of cold. That makes no sense. Whatever, it's not like you're writing an official report. He gasps, and his eyes go wide.

"Oh god," he whispers. "It really does...they were right."

"Right about what?" you ask.

"About you feeling warm," he smiles. "I think...you can try more, if you like."

You scoot up on your knees and lean forward, wrapping your arms softly around him. He nuzzles against you, and it feels so nice. Never in a hundred years did you think Mettaton would ever be comfortable enough to let you see him like this, and you feel so lucky, so loved.

"Thank you," you whisper, rubbing gentle circles into his back.

"I should be thanking you," he moves back and beams up at you, his eyes a bit misty.

He just looks so adorable like this, you don't even think about what you're doing until you've already leaned down and kissed him full on the mouth. If the sweetness of his soul could be made into a cloud, this is what it would taste like. When you draw back, his whole body is glowing.

He moves further back, and with a soft shimmer he sinks back down into his body. His soul still glows when he opens his eyes again, and the first thing he does is pull you close and kiss you deeply. His arms lift you up, and you don't even have to ask what he has in mind, you've done this so many times now.

The bath is already drawn, just hot enough to be comfortable. He washes your back; you wash the makeup from his face. Thankfully, the side of his neck doesn't need repairs. Neither of you are in any mood to explain a bite mark to Alphys. Once was more than enough. He helps you dry, and you don't know who does it, but when you're back in the bedroom there are new sheets. They're even warm from the dryer.

"Wow," you laugh, stretching out over the delightfully soft covers. "I wish I had a bed like this back at the lab, but there isn't nearly enough room."

"You know, I've been meaning to ask," he plugs in his charging cord and slides up beside you, "is there any reason you couldn't stay here? I know you have work to do at the lab, but..."

You look over at him, and despite everything that just happened _this_ is what makes you blush.

"I..." you blink a few times. "Really? You mean it?"

"Of course I mean it," he runs a hand over your hair. "I rather like the idea of seeing you every day. Outside of the lab, I mean."

"Oh my god," you laugh happily. "I'd love that."

"Good," he curls up beside you and presses a soft kiss to your forehead. "Then consider it done."

You sigh happily and tuck your head against his chest, right above the speaker so you can hear the hum of his digital heartbeat. "I love you, Mettaton."

"I love you too, darling. Sleep well."


End file.
